The original frequency of horn of Car A is 1071 Hz.
Explanation:
Doppler effect describes the change in the frequency of sound waves with respect to the observer. As the sound waves emitted from a source need to travel the air medium to reach observer, it will undergo loss in energy. So there will be change in its frequency compared to original frequency. Depending upon the direction of travel of source and observer the shifting of frequency will vary.
Here vo is the observer velocity and vs is the velocity of the source. So Vo = 15 m/s as car B is the observer and Vs = 35 m/s as car A is the source. And f is the frequency of sound wave at source that is car A.
Similarly, the doppler shift in frequency is the frequency of sound heard by car B which is f' = 1140 Hz. And v is the speed of sound that is v = 343 m/s
1140 = 
f = 1140/1.0649= 1071 Hz.
Thus, the original frequency of horn of Car A is 1071 Hz.
Two objects in physical contact with each other are in thermal equilibrium when they reach the same temperature and an exchange of heat energy no longer occurs.<span> According to HyperPhysics, the relation of thermal equilibrium follows the Zeroth Law of Thermodynamics, which states that “if two systems are at the same time in thermal equilibrium with a third system, they are in thermal equilibrium with each other.” </span>
Answer:
I don't know what you mean about which changes occurred in this process but if its why the dough starts rising then its caused by the carbon dioxide in baking soda and yeast which is a fungus
Answer:
Yes
Explanation:
Accerelation is measured by change in velocity. So naturally, if an object is slowing down, its velocity is decreasing so acceleration is negative. If it is speeding up velocity is increasing so positive acceleration.
(Velocity final - Velocity initial)/t
Note that this does not apply only to gravity, but to all linear accelerations
